android - Refreshing an Activity from service when Active

Question

I've an app where I wish to update the Activity (List activity to be precise) only when the activity from Service is in foreground (Active)

I can use ListActivity Intent but the problem is this brings up activity even when its in background.

I also considered using registerDataSetObserver on ListAdapter but that mandates that cursor should be updated. Updating the Cursor from external service may not be feasible.

Do we have a generic solution to this ?

Answer 1

Do we have a generic solution to this ?

Probably a dozen of them. Here are a few:

• Have the activity register a listener object with the service in onResume() and remove it in onPause()
• Send a private broadcast, picked up by the activity via registerReceiver() when it is in the foreground
• Have the activity supply a "pending result"-style PendingIntent to the service
• Use a ResultReceiver
• Use a ContentProvider, with the activity holding onto a Cursor from the provider, and the service updating the provider

This set of projects demonstrates the first three, in the context of remote services.